Automatic apparatus and method for discovering and designating air targets

Abstract: An automatic apparatus and relevant method for discovering and designating air targets constituted by a transmitter assembly (11) which can be associated with a radar (20) and connected via radio with a portable receiver assembly (12). The portable receiver assembly (12) is further constituted by a headset unit (13), an auxiliary terminal (15) and a receiver unit (14) with a satellite system and data processing electronics. The headset unit (13) comprises an earphone (17) and a Magnetic North sensor (18) and is connected with the receiver unit (14). The portable receiver assembly (12) can orient an operator, by means of audio signals, towards the direction of provenance of a selected target and supply her/him with information relevant to said target by means of sound messages, e.g., digitalized voice.

Description: The present invention relates to an automatic apparatus for discovering and designating air targets and its use. Modern combats are characterized above all by a high mobility and a large dispersion of units on battle field. As a consequence, the anti-aircraft systems are required to secure, or meet, determined requisites, such as, e.g., minimal values of reaction time, action starting time and intervention time. The same systems must simultaneously achieve the highest levels of precision and effectiveness degree. Furthermore, the possibility of frequently modifying the deployment without discontinuing the system operativeness must be provided. All the above can only be secured by those systems which are capable of automatically solving, within reduced times and with the required precision level, the problems of position determining and direction orienting. The apparatuses which are known from the prior art and are presently used to constitute such systems, compute and process the received data, in an autonomous mode. The results of these analyses are ususally reported in alphanumerical mode and are then either displayed on suitable displays, or printed. Inasmuch as not always such results are end values, they require the operator to perform data and cartographic analyses, with consequent time losses. WO 88/02841 relates to an apparatus according to the preamble of claim 1. An orientation device including a magnetic sensor arranged in an item of headgear worn by an observer and adapted to provide the observer with alignment data is known from EP-A-503214. The novel apparatus according to the present invention aims hence at solving these drawbacks, by supplying the operator with an immediate answer, or information data, without that said operator must perform any further analyses of the received data. A purpose of the present invention is of providing a standalone and automatic apparatus which is capable of receiving a data string from an external source and reporting to the operator the same data, or the apparatus operating statuses, by voice. Another purpose of the apparatus is of enabling the position to be determined without the aid of cartographic procedures and known points. It furthermore should be capable of supplying the operator with orienting data referred to a precise reference direction. The apparatus must furthermore be capable of determining, by using suitable algorithms, the most dangerous menace and hence commanding, by means of audio signals, the operator orienting towards the direction where the selected target is. Another purpose is also of supplying the operator with distance information and other characteristics of the selected target, by sound messages, including real-time updating the information as to any meaningful changes which may have occurred. Not last, and not least purpose of the present invention is the configuration of the instant apparatus, which must be such as to secure simplicity in use and in servicing the single parts, or devices. Furthermore, the apparatus should have as small overall dimensions and total weight, as possible. In order to achieve these purposes, an automatic apparatus for discovering and designating air targets according to claim 1. The structural and functional characteristcs and the advantages of an apparatus according to the present invention will be better understood from the following exemplifying, non-limitative disclosure in detail thereof, made by referring to the accompanying drawings, in which: Figure 1 is a perspective view of an automatic apparatus for discovering and designating air targets, according to the present invention; Figure 2 is a block diagram of the apparatus of Figure 1, and Figure 3 is a schematic illustration relevant to the operating way of the same apparatus. Referring to Figure 1, an automatic apparatus for discovering and designating air targets is shown, which is essentially composed by a transmitter assembly 11 and a portable receiver assembly 12. Said transmitter assembly 11 is usually sited at a radar watching system and is connected, via radio, with the portable receiver assembly 12. The receiver assembly 12 is constituted by a headset unit 13, a receiver unit 14 and an auxiliary terminal 15. The transmitter assembly 11, which receives from discovery radar the information about the air menace, transmits then the data relating to the targets, e.g., within the VHF band, to the receiver assembly 12. The headset unit 13, which is composed by a headset 16, and earphone 17, with which a live-voice device and a Magnetic North sensor 18 can be associated, supplies the operator with the angular divergence of her/his sight line from the Magnetic North, and, furthermore, by means of its earphones 17, transmits the audio signals and the sound messages relevant to the direction of provenance and the characteristics of the menace. The receiver unit 14 is essentially subdivided into three modules, i.e., a base support, a radio module and a supply module. In the base support, several main modules and sensors are installed, such as a data module, a data processing electronic system and a G.P.S. satellite system. The apparatus, i.e., the receiver assembly 12 is furthermore provided with an auxiliary terminal 15, and with an auxiliary connector 38, which can be connected with a computer in order to enable the operating scenario to be reproduced and all of the characteristics of the targets and apparatus statuses to be monitored. The auxiliary terminal 15 supplies the operator with various auxiliary information relevant to targets, terrain and selected weapon. It furthermore makes it possible the audio signals from the earphone to be regulated or signals or displays the main failures or operating conditions. In any case, it performs a secondary task, and the use thereof is not necessary for the remaining portion of the apparatus to operate correctly and, however, in no way does it change the characteristics thereof. In Figure 2, the main block diagram of the apparatus according to the present invention is displayed. As one may see from this Figure, a first data adapter module 19, incorporated to the transmitter assembly 11, is connected with the discovery radar 20, from which it receives signals, i.e., the data relevant to targets. The same adapter module 19 is also connected with a transmitter radio Tx 21, which transmits such data to the receiver radio Rx 22 of the receiver unit 14, i.e., installed in the receiver assembly 12. The radio set Rx 22 is connected, in its turn, with a second adapter module 23, which sends the received data to a processor 24. Furthermore, a power supply module 25 is provided in order to feed both the processor 24 and the module 23 and radio set Rx 22, and therefore turn the receiver assembly 12 into a standalone one. The processor 24 communicates with a G.P.S. satellite sensor 26 which, by exploiting a satellite constellation, communicates to the same processor the current position on terrain. Furthermore, the processor 24 receives further data relevant to the angular position on terrain from the Magnetic North sensor 18, which is capable of supplying an angular position information referred to Magnetic North. The received and processed data is then transmitted to earphones 17 and auxiliary terminal 15. The apparatus is provided with an acoustical interface, so all main information data is sent to the operator by means of audio signals and messages. For example, a digitalized voice reproduces the transmitted information by means of the radio connection, whilst modulated sounds keep the operator informed on the apparatus operating status and orient her/him towards the target provenance direction. As one can see from Figure 3, the apparatus detects the position of the target 27 as referred to two zones, one of which is a discovery zone 29, and the other one is an engagement zone 30. On the contrary, all targets which are in an external zone 28 are located by the radar, but their presence is ignored until they enter said discovery zone 29. In fact, if the target 27 is inside the discovery zone 29, the operator 31 is kept informed on the operating configuration and on the targets characteristics by sound messages. A first message relates the alarm status and defines the operating conditions of battle units. For example, the operator is informed whether the attack is an imminent attack, a probable attack, or the attack does not exist, and furthermore is informed whether it is only a matter of drill. A second message relates to the identification of the menace and informs the operator whether the discovered aircraft or helicopter is a friendly or an enemy one. A further communication relates to the weapon control command and therefore defines whether fire must be free, conditioned, or forbidden. These messages are supplied once only and are only repeated when changes in conditions occur. The operator receives an indication as to the type of trajectory 33 which the target 27 is being running along. The value in metres is the distance 34 which the target will have from the operator 31 when it will be abeam of her/him. This indication is supplied once for each target, and every time when the distance data changes. A distance data relates to a distance 35 of the target. The message is reported with kilometric variation with a minimal time interval between the end of the message and the beginning of another. When the minimal time interval between both messages is exceeded, and no variations occur in data, the message is repeated. When the menacing target enter the engagement zone 30, the operator 31 automatically receives an audio signal from her/his earphone 17. This is a stereo signal which is released on the right hand side or on the left hand side, thus indicating the rotation direction for the operator to orient towards the target. For an angle of 180°, i.e., from +90° to -90°, relatively to the direction of provenance of the target, the signal is modulated in frequency and amplitude, which decrease as the operator approaches the target provenance direction. A signal absence means that the operator is exactly oriented in the direction of provenance of the selected target, and that the angle between her/his orientation line and an aircraft 27 provenance direction line 33 is of zero degree. For angle values outside of the angle of 180°, i.e., of ±90°, the signal reaches its saturation at its highest values. When the absence of audio signal is reached, acoustical messages are sent, which bear information relevant to the engaged target. To the operator a residual time is signalled, which is the residual time remaining for the operator to start the fire action. Such a time also takes into account the flight time of the projectile used, and therefore is released when the target distance is shorter than weapon range, as indicated with the reference numeral 36. The same data is associated with the distance data 35 and is repeated under the same conditions. When the selected target is outside of the weapon range, in the moving away direction, e.g., in the point indicated with the reference numeral 37, the operator receives an acoustical out-of-range message. If the apparatus finds, inside the interior of the engagement zone 30, a target which it considers to have higher priority than the selected target, the apparatus with indicate these new conditions to the operator. In the case when the operator selects the second target, with said selection taking place by means of one single operator's head movement, the apparatus will communicate to the operator that it has ackowledged her/his will. This information is followed by a new audio position correction signal. In all cases, thanks to the Magnetic North sensor 18 incorporated to the headset 16 of the operator, and aligned with her/his sight line, said position correction is immediate and very precise. This makes it possible the operator movements to be monitored in real time with high precision. The position correction signal is sent for those target distance values which are shorter than a preselected distance, which obviously will depend on the currently used weapon type. This signal is with higher priority than any other message types, in order to make it possible the immediate operator's response to be privileged. Under these conditions, the operator must position her/himself in the target provenance direction if she/he wishes to receive the other information data, because "voice" information is only supplied when the audio signal is absent. The signal absence is identified with an angular zone further associated with the precision of the position correction which one wishes to obtain. The amplitude of this angle is variable and is linked to the discovery apparatus. When a sight discovery is carried out, it is not necessary to have a narrow zone, because human eye sight range is larger than 20°. If, on the contrary, the discovery optics is an infrared optics with a sight range of, e.g., 8°, the angular zone must necessarily be given a smaller amplitude, so as to secure that the target will be discovered. The system, i.e., the apparatus according to the present invention is capable of securing, thanks to its positioning sensors, the G.P.S. and the Magnetic North sensor, better precision values than 5°. In the case when a second, higher-priority target is discovered inside the engagement zone, the operator is informed of this condition, as disclosed hereinabove. In any cases, as she/he could already be in an advanced phase of engagement sequence, e.g., ready to open fire, the operator will be given the possibility of freely deciding. Obviously, under these conditions, the operator cannot change her/his target any longer, or this choice would not be advantageous. In the case when the operator decides to change her/his target, she/he must rotate her/his head by a large angle than 60°, during a shorter time than 2 seconds. This head rotation must be carried out within a time interval of 10 seconds since the information was communicated. If the operator does not succeed in performing her/his head rotation during the preestablished time, or she/he does not accept the designation, or the conditions which determined the new designation message generation no longer exist, the operator receives an audio signal which indicates the missed acceptance of the new engagement. If the new designation message conditions continue to remain true, the new designation message will be repeated after a preestablished time, e.g., after 10 seconds. The apparatus is furthermore capable of sending an acoustical message which indicates to the operator that not-well-identified noise is being received by radar. The main advantage of the automatic apparatus for discovering and designating air targets is given by the possibility of transmitting to the operator all main information by means of audio signals. Meaningful is the possibility of receiving information during target engagement, with the operator being thus supplied with a continuous updating of the target characteristics until the fire opening time has come. Another great advantage is given by the fact that the data, transmitted as words or sound signals correspondingly to the nature of the message, are ultimate and referred to the operator position, and therefore do not require that the operator performs any data analysis and cartographic activities, with consequent time losses.

Claims: Automatic apparatus for discovering and designating air targets constituted by a transmitter assembly (11) which can be associated with a radar (20) and can be connected, via radio, with a receiver (12), said receiver comprising an auxiliary terminal (15), a receiver unit (14) and data processing electronics (24), characterised in that said receiver unit (14) comprises a satellite system (26), said receiver assembly (12) is a portable receiver assembly and further comprises a headset unit (13) comprising an earphone (17) and a Magnetic North sensor (18), being suitable for being connected with said receiver unit (14), and said receiver unit (14) and said headset unit (13) are suitable for orienting an operator (31), by means of audio signals, towards the direction of provenance of a selected target (27), and supplying her/him with information relevant to the same target (27), by means of sound messages. Apparatus according to claim 1, characterized in that said apparatus is capable of selecting air target (27) relatively to two zones (29, 30), one of which is a discovery zone (29) and the other one is an engagement zone (30). Apparatus according to claim 1, characterized in that said audio signal is a stereo signal which is emitted, when the target (27) is within the engagement zone (30), only from one side of said earphone (17), thus determining the direction of rotation of said operator (31) towards said target provenance direction. Apparatus according to claim 3, characterized in that the amplitude and frequency of said audio signal decrease as said target provenance direction is approached by the operator (31). Apparatus according to claim 3, characterized in that an absence of said audio signal indicates that said operator (31) is exactly oriented towards said target provenance direction. Apparatus according to claim 5, characterized in that when said audio signal is absent, the operator (31) receives information as to the characteristcs of said target (27). Apparatus according to claim 1, characterized in that said acoustical messages are a digitalized voice. Apparatus according to claim 1, characterized in that said acoustical message is an indication as to the type of trajectory said target (27) is running along. Apparatus according to claim 1, characterized in that said acoustical message is an information as to a certain distance of said target (27). Apparatus according to claim 1, characterized in that said acoustical message is an information as to a certain residual time for fire opening action. Apparatus according to claim 2, characterized in that said audio signal is an information as to an angular position of said target (27). Apparatus according to claim 1, characterized in that said acoustical messages are suitable for being repeated at any meaningful changes thereof. Apparatus according to claim 1, characterized in that said acoustical messages are suitable for being repeated after a preestablished maximal time. Apparatus according to claim 1, characterized in that said Magnetic North sensor (18) is aligned with the sight line of said operator (31). Apparatus according to claim 3, characterized in that the amplitude of the zone of absence of said audio signal is variable as a function of desired precision. Apparatus according to claim 1, characterized in that it is suitable for selecting a higher-priority target at any time, and for sending a relevant signal to said operator (31). Apparatus according to claim 1, characterized in that it is suitable for being connected with a computer and is suitable for supplying various information as to the target (27). Use of the apparatus according to claim 1 in a target engagement sequence comprising the following steps: target discovery step; step of transmission of data relevant to target discovery; step of supplying the operator (31) with the information of target presence, by means of acoustical messages; step of operator orienting by means of said audio signal, in the direction of provenance of said target (27), step of audio signal absence when the operator (31) is in the correct orientation position; step of signalling target characteristic information by means of acoustical messages. Use according to claim 18, characterized in that during the engagement sequence a further step of signalling a new target (27), regarded as having higher priority than said selected target, is carried out. Use according to claim 19, characterized in that said step of signalling a new, higher-priority target is followed by a possible step of operator's position correction. Use according to claim 19, characterized in that the acceptance of said new, higher-priority target is signalled by the operator (31), by her/his head rotation.

Inventors: AGRUSA MAURO, IARDELLA CARLO ALBERTO, AGRUSA, MAURO, IARDELLA, CARLO ALBERTO
Applicants: FINMECCANICA SPA, FINMECCANICA S.P.A.
Application year: 1994
Main classification: F41G3
IPC codes: F41G3